In an immunodiffusion test to diagnose the fungal disease histoplasmosis,a patient's serum is placed in a well in an agar plate.In a positive test,a precipitate forms as the serum diffuses from the well and meets material diffusing from a second well.In this test process,what is the most likely identity of the material in the second well?
A)antibodies
B)a purified fungal antigen
C)entire fungal cells
D)a purified protozoan antigen
E)red blood cells

Question

Quizplus · Accepted Answer

The material in the second well is most likely a purified fungal antigen because in an immunodiffusion test, it is common to use a purified antigen in the second well to allow the antibodies present in the patient's serum to react and form a precipitate. Entering Fungal cells or red blood cells into the second well would not be useful for this test, and a purified protozoan antigen would not be relevant for a test diagnosing histoplasmosis, which is caused by a fungus.

In an Immunodiffusion Test to Diagnose the Fungal Disease Histoplasmosis,a